The resistance between two opposite faces of a square thin film of area 1 mm2 having a thickness of 1 m if the resistivity of the material is 10-6 Ω will be:
Correct answer: C. 1 Ω
- A. 1000 Ω
- B. 100 Ω
- C. 1 Ω
- D. 10 Ω
Explanation
Given data Area, A= 1mm2 Resistivity, ρ= 10-6Ωm Thickness, x= 10-6m Now we have Resistance, R=ρl/A where A= = length (l) x thickness (x) Thus, R= ρll.x Or R= ρ/x Substituting the values , R= 10-6Ωm10-6m R= 1Ω
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About Resistance and Resistivity
Resistance measures opposition to current in a conductor and follows R = V/I for an ohmic conductor, while resistivity is an intrinsic property of the material. Questions use R = ρL/A, examine effects of length, cross-sectional area and temperature, and distinguish resistance, resistivity, conductance and conductivity.
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